The Diversified SUA Series is designed to protect three-phase equipment against Phase Loss, Under Voltage, and Phase Reversal conditions. With normal operating voltages applied in the proper ABC sequence, the internal relay will energize (PICKUP). When incorrect phase sequence or phase loss occurs or the three-phase voltages fall below the drop out voltages, the relay will de-energize (DROPOUT). Both Delta and Wye systems may be monitored with the ATC Diversified SUA monitors. In Wye systems, connections to neutral are not required.

The SUA unit has out put ratings of SPDT, 345 VA Inductive; 10 Amps Resistive @ 240 VAC. The drop out voltage is 357-398 on 1 phase and 387-432 on 3 phase. The SUA440ASA requires an octal plug in socket and has a screwdriver adustment. The operating voltage range is 430-480 VAC. ATC Diversified part number is SUA440ASA.